Asphalt has been the subject of exhaustive study to improve characteristics for use in paving. Various properties of asphalt are manipulated to produce a product that has the appropriate wear properties, rut resistance, fatigue and low temperature cracking resistance, adhesion strength, viscosity and pour point. Rut resistance is resistance to longitudinal surface depressions in the wheel paths.

Adhesion strength is the maximum adhesion strength of the joint sealant and the joint reservoir, including but not limited to, between the aggregate and the binder.